National foreword

This British Standard is the UK implementation of EN ISO16047:2005+A1:2012. It is identical to ISO 16047:2005, incorporating amendment 1:2012. It supersedes BS 7371, which is withdrawn.

The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to ISO text carry the number of the ISO amendment. For example, text altered by ISO amendment 1 is indicated by .

The UK participation in its preparation was entrusted to Technical Committee FME/9, Fasteners.

A list of organizations represented on this committee can be obtained on request to its secretary.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2005.

Foreword to amendment A1

This document (EN ISO16047:2005/A1:2012) has been prepared by Technical Committee ISO/TC2 “Fasteners” in collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by DIN.

This Amendment to the European Standard EN ISO16047:2005 shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2013, and conflicting national standards shall be withdrawn at the latest by March 2013.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO16047 was prepared by Technical Committee ISO/TC2, Fasteners, Subcommittee SC1, Mechanical properties of fasteners.

This European Standard was approved by CEN on 17 January 2005.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Foreword

This document (EN ISO16047:2005) has been prepared by Technical Committee ISO/TC2 "Fasteners" in collaboration with Technical Committee CEN/TC 185 "Threaded and non-threaded mechanical fasteners and accessories", the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2005, and conflicting national standards shall be withdrawn at the latest by August 2005.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice

The text of ISO 16047:2005 has been approved by CEN as EN ISO16047:2005 without any modifications.

Endorsement notice

The text of ISO16047:2005/Amd 1:2012 has been approved by CEN as a EN ISO16047:2005/A1:2012 without any modification.

1 Scope

This International Standard specifies the conditions for carrying out torque/clamp force tests on threaded fasteners and related parts.

It is applicable, basically, to bolts, screws, studs and nuts made of carbon steel and alloy steel, whose mechanical properties are specified in ISO898‑1 and ISO898‑2, having ISO metric threads with thread sizes M3 to M39. It is also applicable to the combination of other externally and internally threaded fasteners with a triangular ISO thread according to ISO68-1.

It is not applicable to set screws and similar threaded fasteners that are not under tensile stresses, nor to screws which form their own mating thread Text deleted.

Unless otherwise agreed, the tests are carried out at room temperature. However, tests carried out under standard conditions are made at a temperature of 10 °C to 35 °C.

This method allows determination of the tightening characteristics of threaded fasteners and related parts.

2 Normative references

3 Terms and definitions

4 Symbols and their designations

5 Principle of test

5.1 General

5.2 Determination of coefficients of friction

5.3 Determination of torque coefficient K (K-factor)

5.4 Determination of ratio T/F

6 Apparatus

6.1 Testing machine

6.2 Test fixture

7 Test parts

7.1 General

7.2 Test-bearing plates or test washers

7.3 Test nuts for testing bolts, screws and studs

7.4 Test bolts or test screws for testing nuts

8 Testing under standard conditions

9 Testing under specific conditions

10 Evaluation of results

10.1 Determination of torque coefficient K

10.2 Determination of coefficient of total friction µ_tot

10.3 Determination of coefficient of friction between threads µ_th

10.4 Determination of coefficient of friction between bearing surfaces µ_b

10.5 Determination of yield clamp force F_y

10.6 Determination of yield tightening torqueT_y

10.7 Determination of ultimate clamp forceF_u

10.8 Determination of ultimate tightening torqueT_u

11 Test report

11.1 General

11.2 Description of fasteners to be tested

11.3 Description of test parts

11.4 Testing machine

11.5 Test fixture

11.6 Environmental conditions

11.7 Specific conditions

11.8 Test results

Bibliography

BS EN ISO 16047:2005+A1:2012

Fasteners. Torque/clamp force testing

Current, Under Review

Published:

31 Oct 2020